/* -------------------------------------------------------------------------
 *
 *	  EUC_KR and MULE_INTERNAL
 *
 * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *	  src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
 *
 * -------------------------------------------------------------------------
 */

#include "postgres.h"
#include "knl/knl_variable.h"
#include "fmgr.h"
#include "mb/pg_wchar.h"

PG_MODULE_MAGIC;

PG_FUNCTION_INFO_V1(euc_kr_to_mic);
PG_FUNCTION_INFO_V1(mic_to_euc_kr);

extern "C" Datum euc_kr_to_mic(PG_FUNCTION_ARGS);
extern "C" Datum mic_to_euc_kr(PG_FUNCTION_ARGS);

/* ----------
 * conv_proc(
 *		INTEGER,	-- source encoding id
 *		INTEGER,	-- destination encoding id
 *		CSTRING,	-- source string (null terminated C string)
 *		CSTRING,	-- destination string (null terminated C string)
 *		INTEGER		-- source string length
 * ) returns VOID;
 * ----------
 */
static void euc_kr2mic(const unsigned char* euc, unsigned char* p, int len);
static void mic2euc_kr(const unsigned char* mic, unsigned char* p, int len);

Datum euc_kr_to_mic(PG_FUNCTION_ARGS)
{
    unsigned char* src = (unsigned char*)PG_GETARG_CSTRING(2);
    unsigned char* dest = (unsigned char*)PG_GETARG_CSTRING(3);
    int len = PG_GETARG_INT32(4);

    CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_KR, PG_MULE_INTERNAL);

    euc_kr2mic(src, dest, len);

    PG_RETURN_VOID();
}

Datum mic_to_euc_kr(PG_FUNCTION_ARGS)
{
    unsigned char* src = (unsigned char*)PG_GETARG_CSTRING(2);
    unsigned char* dest = (unsigned char*)PG_GETARG_CSTRING(3);
    int len = PG_GETARG_INT32(4);

    CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_EUC_KR);

    mic2euc_kr(src, dest, len);

    PG_RETURN_VOID();
}

/*
 * EUC_KR ---> MIC
 */
static void euc_kr2mic(const unsigned char* euc, unsigned char* p, int len)
{
    int c1;
    int l;

    while (len > 0) {
        c1 = *euc;
        if (IS_HIGHBIT_SET(c1)) {
            l = pg_encoding_verifymb(PG_EUC_KR, (const char*)euc, len);
            if (l != 2)
                report_invalid_encoding(PG_EUC_KR, (const char*)euc, len);
            *p++ = LC_KS5601;
            *p++ = c1;
            *p++ = euc[1];
            euc += 2;
            len -= 2;
        } else { /* should be ASCII */
            if (c1 == 0)
                report_invalid_encoding(PG_EUC_KR, (const char*)euc, len);
            *p++ = c1;
            euc++;
            len--;
        }
    }
    *p = '\0';
}

/*
 * MIC ---> EUC_KR
 */
static void mic2euc_kr(const unsigned char* mic, unsigned char* p, int len)
{
    int c1;
    int l;

    while (len > 0) {
        c1 = *mic;
        if (!IS_HIGHBIT_SET(c1)) {
            /* ASCII */
            if (c1 == 0)
                report_invalid_encoding(PG_MULE_INTERNAL, (const char*)mic, len);
            *p++ = c1;
            mic++;
            len--;
            continue;
        }
        l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char*)mic, len);
        if (l < 0)
            report_invalid_encoding(PG_MULE_INTERNAL, (const char*)mic, len);
        if (c1 == LC_KS5601) {
            *p++ = mic[1];
            *p++ = mic[2];
        } else
            report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_KR, (const char*)mic, len);
        mic += l;
        len -= l;
    }
    *p = '\0';
}

